The aim of the proposal is to predict three dimensional tooth displacements for any given static force-couple applied to human incisors and to estimate stress-strain characteristics at the tooth-periodontal ligament and periodontal ligament-alveolar bone interfaces. A mathematical model for prediction will be synthesized using the finite element technique and experimental data. The experimental component of the study includes measurement of geometric parameters of the tooth and the periodontium and force-tooth displacement characteristics by means of a piezoelectric transducer-holography system. The basic contribution of the analytical portion of this work lies in a synthesis technique which will be developed herein. These months will be a considerable improvement over present analytical techniques. Histological studies will allow stress in the periodontal ligament to be related to biological response which is unique since previous studies relate applied force and bone remodeling.